The main functions of the BLTouch are the same as the ordinary automatic leveling sensor, consisting of RC servo mechanism and micro switch. Thus, the BLTouch can be applied on almost any board. The BLTouch is fulfilled with simple structure and high precision by using progressively designed solenoid valve and hall sensor. It aims for user convenience and enjoyable printing by adding many smart functions, such as self-test, alarm, release alarm and touch switch mode, blue LED for servo signal indicating and Z-probe(Zmin) testing.